University of Leicester researchers have revealed that coastal animals have their own biological tidal timer, which is separate from their 24-hour body clock.
Experts from the University's Department of Genetics have published a paper in Current Biology which reveals the discovery of an independent clock driving coastal animals' tidal rhythms.
The paper, Dissociation of Circadian and Circatidal Timekeeping in the Marine Crustacean Eurydice pulchra, follows nearly ten years of research by Leicester geneticists, along with colleagues at the Universities of Bangor, Aberystwyth and Cambridge.
The researchers observed the behaviour of Eurydice pulchra, the speckled sea louse which lives along the sandy shores around the UK coast.
Eurydice have a regular 12.4 hour swimming cycle matching the incoming tides which sees them actively swimming around to find food as the tide comes in, and burying themselves in the sand as the tide goes out.
Eurydice also have a 24 hour 'circadian' rhythm in pigmented cells called melanophores, which grow during the day (acting as sunscreen) and become smaller at night when they are not required.
It had been thought for many years that these patterns of tidal behaviour in coastal organisms were driven by the 24-hour circadian clock, the ubiquitous and genetically encoded 'body clock' which controls the rhythmic behaviour and physiology of almost every terrestrial higher organism, including humans.
But the new paper shows that tidal behaviour is not governed by the circadian clock but is instead controlled by a dedicated 12.4-hour "circatidal pacemaker".
The researchers caught Eurydice from the coast near Bangor every season and monitored their behaviour and clock molecules in laboratories at Bangor and Leicester.
The team were able to "turn off" Eurydice's circadian clock by genetically kno
|Contact: Charalambos Kyriacou|
University of Leicester